Organic light-emitting device

ABSTRACT

An organic light-emitting device includes a first electrode, a second electrode facing the first electrode, and an emission layer disposed between the first electrode and the second electrode. An electron transport region is between the second electrode and the emission layer. The electron transport region includes an electron injection layer including a first component including at least one halide of an alkali metal (Group I), a second component including at least one organometallic compound, and a third component including at least one of a lanthanide metal or an alkaline earth metal (Group II).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2015-0187636, filed on Dec. 28, 2015, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

Exemplary embodiments of the present invention relate to a light-emitting device, and more particularly to an organic light-emitting device.

DISCUSSION OF RELATED ART

Organic light-emitting devices (OLEDs) may be self-emission devices and may have relatively wide viewing angles, relatively high contrast ratios, and relatively short response times. OLEDs may have relatively high brightness, relatively low driving voltage, and relatively fast response speed characteristics, and may produce full-color images.

An OLED, for example, may include a first electrode on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode, which may be sequentially disposed on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, may then recombine in the emission layer to produce excitons. These excitons may transition from an excited state to a ground state, thus generating light.

SUMMARY

One or more exemplary embodiments of the present invention include an organic light-emitting device having a relatively long lifespan and relatively high energy efficiency.

According to an exemplary embodiment of the present invention, an organic light-emitting device includes a first electrode, a second electrode facing the first electrode, and an emission layer disposed between the first electrode and the second electrode. An electron transport region is between the second electrode and the emission layer. The electron transport region includes an electron injection layer including a first component including at least one halide of an alkali metal (Group I), a second component including at least one organometallic compound, and a third component including at least one of a lanthanide metal or an alkaline earth metal (Group II).

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof, with reference to the accompanying drawings, in which:

FIGS. 1 to 4 are schematic diagrams of an organic light-emitting device according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION

Exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. In this regard, the exemplary embodiments may have different forms and should not be construed as being limited to the exemplary embodiments of the present invention described herein. Like reference numerals may refer to like elements throughout the specification and drawings. It will be understood that although the terms “first” and “second” may be used herein to describe various components, these components should not be limited by these terms. Sizes of elements in the drawings may be exaggerated for clarity of description.

According to an exemplary embodiment of the present invention, an organic light-emitting device may include:

a first electrode;

a second electrode facing the first electrode;

an emission layer between the first electrode and the second electrode; and

an electron transport region between the second electrode and the emission layer.

The electron transport region may include an electron injection layer including a first component including at least one halide of an alkali metal (Group I), a second component including at least one organometallic compound, and a third component including at least one of a lanthanide metal and an alkaline earth metal (Group II).

The first component may include one selected from LiF, LiCl, LiBr, Lil, NaF, NaCl, NaBr, Nal, KF, KCl, KBr, Kl, RbF, RbCl, RbBr, Rbl, CsF, CsCl, CsBr, Csl, or any combination thereof. For example, the first component may include on selected from LiF, KCl, KI, RbCl, Rbl, or any combination thereof; however, exemplary embodiments of the present invention are not limited thereto.

The second component may include at least one metal complex. A metal of the metal complex may be selected from lithium (Li), aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), zinc (Zn), or copper (Cu). For example, the second component may include at least one metal complex including a metal selected from Li, Al, Ti, Zr, Hf, Zn, or Cu, and the metal complex may include at least one organic ligand selected from a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenylan oxazole, a hydroxyphenylthiazole, a hydroxydiphenyloxadiazole, a hydroxydiphenylthiadiazol, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, or a cyclopentadiene. In an exemplary embodiment of the present invention, the second component may include at least one metal complex including a metal selected from Li, Al, Ti, Zr, Hf, Zn, or Cu, and may include at least one organic ligand represented by Formula 1 or 2:

In Formulae 1 and 2:

Z₁ and Z₂ may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂),

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, or a carbazolyl group,

e4 may be an integer selected from 1 to 4,

e6 may be an integer selected from 1 to 6, and

* and *′ each independently indicate a binding site to a metal. In an exemplary embodiment of the present invention, the second component may include at least one compound selected from Compounds El-1 to El-9; however, exemplary embodiments of the present invention are not limited thereto.

The third component may include one selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra), or any combination thereof. In an exemplary embodiment of the present invention, the third component may include one selected from Yb or Mg. In an exemplary embodiment of the present invention, the third component may be Yb; however, exemplary embodiments of the present invention are not limited thereto.

A ratio (e.g., volume ratio) of the first component:second component may be 100-x:x (e.g., in which x is greater than 0, but is less than 100), and a ratio (e.g., volume ratio) of the first component:third component may be 100-y:y (e.g., in which y is greater than 0, but is less than 100). In an exemplary embodiment of the present invention, the ratio (e.g., volume ratio) of the first component:second component may be in a range of from about 1:9 to about 9:1, and the ratio (e.g., volume ratio) of the first component:third component may be in a range of about from about 1:9 to about 9:1. In an exemplary embodiment of the present invention, the ratio (e.g., volume ratio) of the first component: third component may be in a range of from about 4:6 to about 6:4; however, exemplary embodiments of the present invention are not limited thereto.

A thickness of the electron injection layer may be in a range of from about 2 Åto about 1,000 Å. For example, the thickness of the electron injection layer may be in a range of from about 10 Å to about 300 Å. When the thickness of the electron injection layer is in any of these ranges, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.

The electron injection layer may be in direct contact with the second electrode.

In an exemplary embodiment of the present invention, the electron injection layer may be formed by co-deposition of the first component, the second component, and the third component. For example, the electron injection layer may include at least one selected from: a film including the second component and the third component, the second component and the third component being dispersed in a matrix including the first component; a film including the first component and the third component, the first component and the third component being dispersed in a matrix including the second component; or a film including the first component and the second component, the first component and the second component being dispersed in a matrix including the third component.

In an exemplary embodiment of the present invention, the electron injection layer may include a first layer and a second layer. The first layer may include two components selected from the first component, the second component, and the third component. The second layer may include one component or two components selected from the first component, the second component, and the third component. For example, the electron injection layer may include: a first layer including the first component and the second component, and a second layer including the third component; a first layer including the first component and the third component, and a second layer including the second component; a first layer including the second component and the third component, and a second layer including the first component; a first layer including the first component and the second component, and a second layer including the first component and the third component; a first layer including the first component and the second component, and a second layer including the second component and the third component; a first layer including the first component and the third component, and a second layer including the first component and the second component; a first layer including the first component and the third component, and a second layer including the second component and the third component; a first layer including the second component and the third component, and a second layer including the first component and the second component; or a first layer including the second component and the third component, and a second layer including the first component and the third component. In an exemplary embodiment of the present invention, the electron injection layer may include: a first layer including the first component and the second component and not including the third component, and a second layer including the third component and not including the first component and the second component; a first layer including the first component and the third component and not including the second component, and a second layer including the third component and not including the first component and the second component; a first layer including the second component and the third component and not including the first component, and a second layer including the first component and not including the second component and the third component; a first layer including the first component and the second component and not including the third component, and a second layer including the first component and the third component and not including the second component; a first layer including the first component and the second component and not including the third component, and a second layer including the second component and the third component and not including the first component; a first layer including the first component and the third component and not including the second component, and a second layer including the first component and the second component and not including the third component; a first layer including the first component and the third component and not including the second component, and a second layer including the second component and the third component and not including the first component; a first layer including the second component and the third component and not including the first component, and a second layer including the first component and the second component and not including the third component; or a first layer including the second component and the third component and not including the first component, and a second layer including the first component and the third component and not including the second component. In an exemplary embodiment of the present invention, the electron injection layer may include: a first layer consisting of the first component and the second component, and a second layer consisting of the third component; a first layer consisting of the first component and the third component, and a second layer consisting of the second component; a first layer consisting of the second component and the third component, and a second layer consisting of the first component; a first layer consisting of the first component and the second component, and a second layer consisting of the first component and the third component; a first layer consisting of the first component and the second component, and a second layer consisting of the second component and the third component; a first layer consisting of the first component and the third component, and a second layer consisting of the first component and the second component; a first layer consisting of the first component and the third component, and a second layer consisting of the second component and the third component; a first layer consisting of the second component and the third component, and a second layer consisting of the first component and the second component; or a first layer consisting of the second component and the third component, and a second layer consisting of the first component and the third component.

When the first layer includes two components, the first layer may be formed by co-deposition of the two components. For example, the first layer may be a film including the second component dispersed in a matrix including the first component; a film including the third component dispersed in a matrix including the first component; or a film including the third component dispersed in a matrix including the second component.

When the second layer includes two components, the second layer may be formed by co-deposition of the two components. For example, the second layer may be a film including the second component dispersed in a matrix including the first component; a film including the third component dispersed in a matrix including the first component; or a film including the third component dispersed in a matrix including the second component.

In an exemplary embodiment of the present invention, the first layer may be a film including the second component dispersed in a matrix including the first component, and the second layer may be a film including the third component; the first layer may be a film including the third component dispersed in a matrix including the first component, and the second layer may be a film including the second component; or the first layer may be a film including the third component dispersed in a matrix including the second component, and the second layer may be a film including the first component. In an exemplary embodiment of the present invention, the first layer may be a film including the second component dispersed in a matrix including the first component, and the second layer may be a film consisting of the third component; the first layer may be a film including the third component dispersed in a matrix including the first component, and the second layer may be a film consisting of the second component; or the first layer may be a film including the third component dispersed in a matrix including the second component, and the second layer may be a film consisting of the first component.

In an exemplary embodiment of the present invention, the first layer may be a film including the second component dispersed in a matrix including the first component, and the second layer may be a film including the third component dispersed in a matrix including the first component; the first layer may be a film including the second component dispersed in a matrix including the first component, and the second layer may be a film including the third component dispersed in a matrix including the second component; the first layer may be a film including the third component dispersed in a matrix including the first component, and the second layer may be a film including the second component dispersed in a matrix including the first component; the first layer may be a film including the third component dispersed in a matrix including the first component, and the second layer may be a film including the third component dispersed in a matrix including the second component; the first layer may be a film including the third component dispersed in a matrix including the second component, and the second layer may be a film including the second component dispersed in a matrix including the first component; or the first layer may be a film including the third component dispersed in a matrix including the second component, and the second layer may be a film including the third component dispersed in a matrix including the first component.

In an exemplary embodiment of the present invention, the first layer may include or consist of the first component and the third component, and the second layer may include or consist of the second component. The ratio (e.g., volume ratio) of the first component:third component may be in a range of from about 1:9 to about 9:1. For example, the ratio (e.g., volume ratio) of the first component:third component may be in a range of from about 4:6 to about 6:4; however, exemplary embodiments of the present invention are not limited thereto.

When the electron injection layer includes the first layer and the second layer, the first layer may be in direct contact with the second electrode and the second layer may be disposed between the first layer and the emission layer. In an exemplary embodiment of the present invention, the second layer may be in direct contact with the second electrode and the first layer may be disposed between the second layer and the emission layer. In an exemplary embodiment of the present invention, the first layer may be in direct contact with the second layer.

A thickness of each of the first layer and the second layer may be in a range of from about 1 Å to about 500 Å. For example, the thickness of each of the first layer and the second layer may be in a range of from about 5 Å to about 300 Å. When the thicknesses of the first layer and the second layer are in any of these ranges, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.

In an exemplary embodiment of the present invention, the electron injection layer may consist of a first layer and a second layer. The first layer may include two components selected from the first component, the second component, and the third component. The second layer may include one component or two components selected from the first component, the second component, and the third component. In an exemplary embodiment of the present invention, the electron injection layer may consist of a first layer and a second layer. The first layer may include two components selected from the first component, the second component, and the third component. The second layer may include one component or two components selected from the first component, the second component, and the third component. In an exemplary embodiment of the present invention, the electron injection layer may consist of a first layer and a second layer. The first layer may consist of two components selected from the first component, the second component, and the third component. The second layer may consist of one component or two components selected from the first component, the second component, and the third component.

In an exemplary embodiment of the present invention, the electron injection layer may include a first layer, a second layer, and a third layer. The first layer may include the first component, the second layer may include the second component, and the third layer may include the third component. The first layer may include the first component and might not include the second component and the third component. The second layer may include the second component and might not include the first component and the third component. The third layer may include the third component and might not include the first component and the second component. The first layer may consist of the first component, the second layer may consist of the second component, and the third layer may consist of the third component.

In an exemplary embodiment of the present invention, the electron injection layer may consist of a first layer, a second layer, and a third layer. The first layer may include the first component, the second layer may include the second component, and the third layer may include the third component. The first layer may include the first component and might not include the second component and the third component. The second layer may include the second component and might not include the first component and the third component. The third layer may include the third component and might not include the first component and the second component. The first layer may consist of the first component, the second layer may consist of the second component, and the third layer may consist of the third component.

When the electron injection layer includes a first layer, a second layer, and a third layer, the first layer may be in direct contact with the second layer and the first layer may be in direct contact with the third layer; or the second layer may be in direct contact with the third layer. In an exemplary embodiment of the present invention, the first layer may be in direct contact with the second layer and the second layer may be in direct contact with the third layer. The first layer may be in direct contact with the second layer and the first layer may be in direct contact with the third layer; or the first layer may be in direct contact with the third layer and the second layer may be in direct contact with the third layer.

When the electron injection layer includes a first layer, a second layer, and a third layer, the first layer may be in direct contact with the second electrode, and the second layer and the third layer may be disposed between the first layer and the emission layer. In an exemplary embodiment of the present invention, the third layer may be in direct contact with the second electrode, and the first layer and the second layer may be disposed between the third layer and the emission layer.

A thickness of each of the first layer, the second layer, and the third layer may be in a range of from about 1 Å to about 300 Å. For example, the thickness of each of the first layer, the second layer, and the third layer may be in a range of from about 5 Å to about 200 Å. When the thicknesses of the first layer, the second layer, and the third layer are in any of these ranges, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.

An organic light-emitting device including the electron injection layer including the first component, which includes at least one halide of an alkali metal (Group I), the second component, which includes at least one organometallic compound, and the third component, which includes at least one of a lanthanide metal and an alkaline earth metal (Group II), may have increased electron injection speed by lowering an electron injection barrier through a combination of the first component and the third component. When the electron injection layer further includes the second component, the charge balance may be increased, and thus an organic light-emitting device including the electron injection layer may exhibit relatively high efficiency and relatively low driving voltage.

FIGS. 1 to 4 are schematic diagrams of an organic light-emitting device according to an exemplary embodiment of the present invention.

FIG. 1 is a schematic view of an organic light-emitting device 10 according to an exemplary embodiment of the present invention. The organic light-emitting device 10 may include a first electrode 110, an organic layer 150, and a second electrode 190.

A structure of an organic light-emitting device according to an exemplary embodiment of the present invention and a method of manufacturing an organic light-emitting device according to an exemplary embodiment of the present invention will be described in more detail below with reference to FIG. 1.

Referring to FIG. 1, a substrate may be disposed under the first electrode 110 or above the second electrode 190. The substrate may be a glass substrate or a plastic substrate, each of which may have relatively high mechanical strength, thermal stability, transparency, surface smoothness, ease of handling and/or water resistance.

The first electrode 110 may be formed by, for example, depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, the material for forming the first electrode 110 may be selected from materials with a relatively high work function to facilitate hole injection.

The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, the material for forming the first electrode 110 may be indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), or any combination thereof; however, exemplary embodiments of the present invention are not limited thereto. When the first electrode 110 is a semi-transmissive electrode or a reflective electrode, the material for forming the first electrode 110 may be magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof; however, exemplary embodiments of the present invention are not limited thereto.

The first electrode 110 may have a single-layered structure or a multi-layered structure including two or more layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO; however, exemplary embodiments of the present invention are not limited thereto.

The organic layer 150 may be disposed on the first electrode 110. The organic layer 150 may include an emission layer.

The organic layer 150 may include a hole transport region between the first electrode 110 and the emission layer, and an electron transport region 157 between the emission layer 155 and the second electrode 190.

The hole transport region may have a single-layered structure including a single material, a single-layered structure including a plurality of different materials, or a multi-layered structure having a plurality of layers, each including a different material.

The hole transport region may include at least one layer selected from a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer.

For example, the hole transport region may have a single-layered structure including a single layer including a plurality of different materials, or a multi-layered structure having a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure. Layers of each structure may be sequentially stacked on the first electrode 110 in the stated order; however, exemplary embodiments of the present invention are not limited thereto.

The hole transport region may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB (also referred to as NPD), β-NPB, TPD, spiro-TPD, spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzene sulfonic acid (Pani/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (Pani/CSA), polyaniline/poly(4-styrenesulfonate) (Pani/PSS), a compound represented by Formula 201, or a compound represented by Formula 202:

In Formulae 201 and 202:

L₂₀₁ to L₂₀₄ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted or unsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstituted C₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer from 0 to 3,

xa5 may be an integer from 1 to 10, and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

For example, in Formula 202, R₂₀₁ and R₂₀₂ may be chemically bonded to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group, and R₂₀₃ and R₂₀₄ may be chemically bonded to to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group.

In an exemplary embodiment of the present invention, in Formulae 201 and 202, L₂₀₁ to L₂₀₅ may each independently be selected from:

a phenylene group, a pentalenylene group, anindenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, or a pyridinylene group; or

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), or —N(Q₃₁)(Q₃₂).

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.

In an exemplary embodiment of the present invention, xa1 to xa4 may each independently be 0, 1, or 2.

In an exemplary embodiment of the present invention, xa5 may be 1, 2, 3, or 4.

In an exemplary embodiment of the present invention, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, or a pyridinyl group; or

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), or —N(Q₃₁)(Q₃₂).

Q₃₁ to Q₃₃ may each independently be as described herein.

In an exemplary embodiment of the present invention, in Formula 201, at least one selected from R₂₀₁ to R₂₀₃ may each independently be selected from:

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, or a dibenzothiophenyl group; or

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, or a dibenzothiophenyl group; however, exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 202, R₂₀₁ and R₂₀₂ may be chemically bonded to each other via a single bond, and/or R₂₀₃ and R₂₀₄ may be chemically bonded to each other via a single bond.

In an exemplary embodiment of the present invention, in Formula 202, at least one selected from R₂₀₁ to R₂₀₄ may be selected from:

a carbazolyl group; or

a carbazolyl group substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, or a dibenzothiophenyl group; however, exemplary embodiments of the present invention are not limited thereto.

The compound represented by Formula 201 may be represented by Formula 201A:

For example, the compound represented by Formula 201 may be represented by Formula 201A(1); however, exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, the compound represented by Formula 201 may be represented by Formula 201A-1; however, exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, the compound represented by Formula 202 may be represented by Formula 202A; however, exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, the compound represented by Formula 202 may be represented by Formula 202A-1; however, exemplary embodiments of the present invention are not limited thereto.

In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1:

L₂₀₁ to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂ to R₂₀₄ may each independently be as described herein,

R₂₁₁ and R₂₁₂ may each independently be the same as R₂₀₃, as described herein, and

R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, or a pyridinyl group.

The hole transport region may include at least one compound selected from Compounds HT1 to HT39; however, exemplary embodiments of the present invention are not limited thereto.

A thickness of the hole transport region may be in a range of from about 100 Å to about 10,000 Å, for example, from about 100 Å to about 1,000 Å. When the hole transport region includes at least one of a hole injection layer and a hole transport layer, a thickness of the hole injection layer may be in a range of from about 100 Å to about 9,000 Å, for example, from about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be in a range of from about 50 Å to about 2,000 Å, for example, from about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within any of these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, and thus, the light emission efficiency of an organic light-emitting device according to an exemplary embodiment of the present invention may be increased. The electron blocking layer may block injection of electrons from the electron transport region 157. The emission auxiliary layer and the electron blocking layer may include the materials described herein.

The hole transport region may include, in addition to the materials described above, a charge-generation material for increasing conductive properties. The charge-generation material may be substantially homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant.

In an exemplary embodiment of the present invention, the p-dopant may have a relatively low lowest unoccupied molecular orbital (LUMO) energy level of about −3.5 eV or less.

The p-dopant may be one selected from a quinone derivative, a metal oxide, or a cyano group-containing compound; however, exemplary embodiments of the present invention are not limited thereto.

For example, the p-dopant may include at least one selected from: a quinone derivative, such as tetracyanoquinonedimethane (TCNQ) and 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ); a metal oxide, such as a tungsten oxide and a molybdenum oxide; and a cyano group-containing compound, such as 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN); or a compound represented by Formula 221; however, exemplary embodiments of the present invention are not limited thereto.

In Formula 221, R₂₂₁ to R₂₂₃ may each independently be selected from: a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, wherein at least one selected from R₂₂₁ to R₂₂₃ may have a substituent selected from a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substituted with —F, a C₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl group substituted with —Br, or a C₁-C₂₀ alkyl group substituted with —I.

When the organic light-emitting device 10 is a full color organic light-emitting device, the emission layer 155 may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a sub-pixel. In an exemplary embodiment of the present invention, the emission layer 155 may have a stacked structure including a red emission layer, a green emission layer, and a blue emission layer, or may include a red light-emitting material, a green light-emitting material, and a blue light-emitting material, which are mixed with each other in a single layer, to emit white light.

The emission layer 155 may include a host and a dopant. The dopant may include at least one selected from a phosphorescent dopant or a fluorescent dopant.

An amount of the dopant in the emission layer 155 may be, for example, in a range of from about 0.01 parts to about 15 parts by weight based on 100 parts by weight of the host; however, exemplary embodiments of the present invention are not limited thereto.

A thickness of the emission layer 155 may be in a range of from about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer 155 is within any of these ranges, relatively high light-emission characteristics may be obtained without a substantial increase in driving voltage.

The host may include a compound represented by Formula 301:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21).   <Formula 301>

In Formula 301:

Ar₃₁₀ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xb11 may be 1, 2, or 3,

L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xb1 may be an integer from 0 to 5,

R₃₀₁ may be selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁) (Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), or —P(═O)(Q₃₀₁)(Q₃₀₂),

xb21 may be an integer from 1 to 5, and

Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group; however, exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 301, Ar₃₀₁ may be selected from:

a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, or a dibenzothiophene group; or

a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, and a dibenzothiophene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), —P(═O)(Q₃₁)(Q₃₂).

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group; however, exemplary embodiments of the present invention are not limited thereto.

In Formula 301, when xb11 is 2 or more, two or more Ar₃₀₁(s) may be chemically bonded to each other via a single bond.

In an exemplary embodiment of the present invention, the compound represented by Formula 301 may be represented by Formula 301-1 or 301-2:

In Formulae 301-1 to 301-2:

A₃₀₁ to A₃₀₄ may each independently be selected from a benzene group, a naphthalene group, a phenanthrene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a pyridine group, a pyrimidine group, an indene group, a fluorene, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, an indole group, a carbazole group, a benzocarbazole group, a dibenzocarbazole group, a furan group, a benzofuran group, a dibenzofuran group, a naphthofuran group, a benzonaphthofuran group, a dinaphthofuran group, a thiophene group, a benzothiophene group, a dibenzothiophene, a naphthothiophene group, a benzonaphthothiophene group, or a dinaphthothiophene group,

X₃₀₁ may be O, S, or N—[(L₃₀₄)_(xb4)-R₃₀₄],

R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ may each independently be as described herein,

L₃₀₂ to L₃₀₄ may each independently be the same as L₃₀₁, as described herein,

xb2 to xb4 may each independently be the same as xb1, as described herein, and

R₃₀₂ to R₃₀₄ may each independently be the same as R₃₀₁ as described herein.

For example, in Formulae 301, 301-1, and 301-2, L₃₀₁ to L₃₀₄ may each independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, or an azacarbazolylene group; or

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolyiene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazoiylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, and oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂).

Q₃₁ to Q₃₃ may each independently be the same as described herein.

In an exemplary embodiment of the present invention, in Formulae 301, 301-1, and 301-2, R₃₀₁ to R₃₀₄ may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, or an azacarbazolyl group; or

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂).

Q₃₁ to Q₃₃ may each independently be the same as described herein.

In an exemplary embodiment of the present invention, the host may include an alkaline earth metal complex. For example, the host may be selected from a Be complex (e.g., Compound H55), a Mg complex, or a Zn complex.

The host may include at least one selected from 9,10-di(2-naphthyl)anthracene (ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), or Compounds H1 to H55; however, exemplary embodiments of the present invention are not limited thereto.

The phosphorescent dopant may include an organometallic complex represented by Formula 401:

In Formulae 401 and 402:

M may be selected from iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), or thulium (Tm),

L₄₀₁ may be selected from a ligand represented by Formula 402,

xc1 may be 1, 2, or 3, in which, when xc1 is 2 or more, two or more L₄₀₁(s) may be identical to or different from each other,

L₄₀₂ may be an organic ligand,

xc2 may be an integer from 0 to 4, in which, when xc2 is 2 or more, two or more L₄₀₂(s) may be identical to or different from each other,

X₄₀₁ to X₄₀₄ may each independently be nitrogen or carbon,

X₄₀₁ and X₄₀₃ may be chemically bonded to each other via a single bond or a double bond, and X₄₀₂ and X₄₀₄ may be chemically bonded to each other via a single bond or a double bond,

A₄₀₁ and A₄₀₂ may each independently be a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group,

X₄₀₅ may be a single bond, *—O—*′, *—S—* ′, *—C(═O)—*′, *—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)═C(Q₄₁₂)-*′, *—C(Q₄₁₁)═*′, or *═C(Q₄₁₁)═*′, in which Q₄₁₁ and Q₄₁₂ may each independently be hydrogen, deuterium, C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group,

X₄₀₆ may be a single bond, O, or S,

R₄₀₁ and R₄₀₂ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₂₀ alkyl group, a substituted or unsubstituted C₁-C₂₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆ ⁻C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), wherein Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a C₆-C₂₀ aryl group, or a C₁-C₂₀ heteroaryl group,

xc11 and xc12 may each independently be an integer from 0 to 10, and

in Formula 402, * and *′ each independently indicate a binding site to M of Formula 401.

In an exemplary embodiment of the present invention, in Formula 402, A₄₀₁ and A₄₀₂ may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, an indene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a carbazole group, a benzimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a dibenzofuran group, or a dibenzothiophene group.

In an exemplary embodiment of the present invention, in Formula 402, X₄₀₁ may be nitrogen and X₄₀₂ may be carbon, or X₄₀₁ and X₄₀₂ may each be nitrogen.

In an exemplary embodiment of the present invention, in Formula 402, R₄₀₁ and R₄₀₂ may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, or a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a phenyl group, a naphthyl group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, or a norbornenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, or a dibenzothiophenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, or a dibenzothiophenyl group; or

—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), or —P(═O)(Q₄₀₁)(Q₄₀₂).

Q_(401 to) Q₄₀₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, or a naphthyl group; however, exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 401, when xc1 is 2 or more, two A₄₀₁(s) among two or more L₄₀₁(s) may be chemically bonded to each other through X₄₀₇, which may be a linking group, or two A₄₀₂(s) among two or more L₄₀₁(s) may be chemically bonded to each other through X₄₀₈, which may be a linking group (see, e.g., Compounds PD1 to PD4 and PD7 below). X₄₀₇ and X₄₀₈ may each independently be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, or *—C(Q₄₁₃)═C(Q₄₁₄)-*′ (e.g., Q₄₁₃ and Q₄₁₄ may each independently be hydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group); however, exemplary embodiments of the present invention are not limited thereto.

In Formula 401, L₄₀₂ may be a monovalent, divalent, or trivalent organic ligand. For example, L₄₀₂ may be selected from a halogen ligand (e.g., acetylacetonate), a carboxylic acid (e.g., picolinate), —C(═O), an isonitrile ligand, —CN, or a phosphorus ligand (e.g., phosphine and phosphite); however, exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, the phosphorescent dopant may be, for example, selected from Compounds PD1 to PD25; however, exemplary embodiments of the present invention are not limited thereto.

The fluorescent dopant may include an arylamine compound or a styrylamine compound.

The fluorescent dopant may include a compound represented by Formula 501:

In Formula 501:

Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₅₀₁ to L₅₀₃ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xd1 to xd3 may each independently be an integer from 0 to 3,

R₅₀₁ and R₅₀₂ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and

xd4 may be an integer from 1 to 6.

an exemplary embodiment of the present invention, in Formula 501, Ar₅₀₁ may be selected from:

a naphthalene group, a heptalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, or an indenophenanthrene group; or

a naphthalene group, a heptalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, and an indenophenanthrene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.

In an exemplary embodiment of the present invention, in Formula 501, L₅₀₁ to L₅₀₃ may each independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, or a pyridinylene group; or

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, or a pyridinyl group.

In an exemplary embodiment of the present invention, in Formula 501, R₅₀₁ and R₅₀₂ may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, or a pyridinyl group; or

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, or —Si(Q₃₁)(Q₃₂)(Q₃₃).

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.

In an exemplary embodiment of the present invention, in Formula 501, xd4 may be 2; however, exemplary embodiments of the present invention are not limited thereto.

For example, the fluorescent dopant may be selected from Compounds FD1 to FD22:

In an exemplary embodiment of the present invention, the fluorescent dopant may be selected from the compounds below; however, exemplary embodiments of the present invention are not limited thereto.

The electron transport region 157 may have a single-layered structure including a single material, a single-layered structure including a plurality of different materials, or a multi-layered structure having a plurality of layers, each including a different material.

The electron transport region 157 may include at least one layer selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer 157′; however, exemplary embodiments of the present invention are not limited thereto.

For example, the electron transport region 157 may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure. The layers of each structure may be sequentially stacked on the emission layer 155 in the stated order; however, exemplary embodiments of the present invention are not limited thereto.

The electron transport region 157 (e.g., a buffer layer, a hole blocking layer, an electron control layer, or an electron transport layer in the electron transport region) may include a metal-free compound including at least one 7 electron-depleted nitrogen-containing ring.

The term “Π electron-depleted nitrogen-containing ring” indicates a C₁-C₆₀ heterocyclic group including at least one *—N═*′ moiety as a ring-forming moiety.

For example, the “Π electron-depleted nitrogen-containing ring” may be a 5-membered to 7-membered heteromonocyclic group having at least one *—N═*′ moiety, a heteropolycyclic group in which two or more 5-membered to 7-membered heteromonocyclic groups each having at least one *—N═*′ moiety are condensed with each other, or a heteropolycyclic group in which at least one 5-membered to 7-membered hetero monocyclic group having at least one *—N═*′ moiety is condensed with at least one C₅-C₆₀ carbocyclic group.

Non-limiting examples of the Π electron-depleted nitrogen-containing ring may include an imidazole, a pyrazole, a thiazole, an isothiazole, an oxazole, an isoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, an indazole, a purine, a quinoline, an isoquinoline, a benzoquinoline, a phthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline, a phenanthridine, an acridine, phenanthroline, phenazine, a benzimidazole, an isobenzothiazole, a benzoxazole, an isobenzoxazole, a triazole, a tetrazole, an oxadiazole, a triazine, thiadiazol, an imidazopyridine, an imidazopyrimidine, or an azacarbazole; however, exemplary embodiments of the present invention are not limited thereto.

For example, the electron transport region 157 may include a compound represented by Formula 601:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21).   <Formula 601>

In Formula 601:

Ar₆₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xe11 may be 1, 2, or 3,

L₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xe1 may be an integer from 0 to 5,

R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ may each independently be C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, and

xe21 may be an integer from 1 to 5.

In an exemplary embodiment of the present invention, at least one xe11 selected from Ar₆₀₁(s) and at least one xe21 selected from R₆₀₁(s) may include the Π electron-depleted nitrogen-containing ring, as described herein.

In an exemplary embodiment of the present invention, in Formula 601, ring Ar₆₀₁ may be selected from:

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, thiadiazol group, an imidazopyridine group, an imidazopyrimidine group, or an azacarbazole group; or

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, thiadiazol group, an imidazopyridine group, an imidazopyrimidine group, and an azacarbazole group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂).

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.

In Formula 601, when xe11 is 2 or more, two or more Ar₆₀₁(s) may be chemically bonded to each other via a single bond.

In an exemplary embodiment of the present invention, in Formula 601, Ar₆₀₁ may be an anthracene group.

In an exemplary embodiment of the present invention, the compound represented by Formula 601 may be represented by Formula 601-1:

In Formula 601-1:

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), and X₆₁₆ may be N or C(R₆₁₆), and at least one selected from X₆₁₄ to X₆₁₆ may be nitrogen,

L₆₁₁ to L₆₁₃ may each independently be the same as L₆₀₁, as described herein,

xe611 to xe613 may each independently be the same as xe1, as described herein,

R₆₁₁ to R₆₁₃ may each independently be the same as R₆₀₁, as described herein, and

R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.

In an exemplary embodiment of the present invention, in Formulae 601 and 601-1, L₆₀₁ and L₆₁₁ to L₆₁₃ may each independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, or an azacarbazolylene group; or

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, or an azacarbazolyl group; however, exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, in Formulae 601 and 601-1, xe1 and xe611 to xe613 may each independently be 0, 1, or 2.

In an exemplary embodiment of the present invention, in Formulae 601 and 601-1, R₆₀₁ and R₆₁₁ to R₆₁₃ may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, or an azacarbazolyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, or an azacarbazolyl group; or

—S(═O)₂(Q₆₀₁) or —P(═O)(Q₆₀₁)(Q₆₀₂).

Q₆₀₁ and Q₆₀₂ may each independently be as described herein.

an exemplary embodiment of the present invention, the electron transport region 157 may include at least one compound selected from Compounds ET1 to ET36; however, exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, the electron transport region 157 may include at least one compound selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), or NTAZ:

A thickness of each of the buffer layer, the hole blocking layer, and the electron may be in a range of from about 20 Å to about 1,000 Å, for example, from about 30 Å to about 300 Å. When the thicknesses of the buffer layer, the hole blocking layer, and the electron control layer are within any of these ranges, relatively high hole blocking characteristics and/or electron control characteristics may be obtained without a substantial increase in driving voltage.

A thickness of the electron transport layer may be in a range of from about 100 Å to about 1,000 Å, for example, from about 150 Å to about 500 Å. When the thickness of the electron transport layer is within any of these ranges, satisfactory electron transport characteristics may be obtained without a substantial increase in driving voltage.

The electron transport region 157 (e.g., an electron transport layer in the electron transport region 157) may further include, in addition to the materials described above, a material including metal.

The material including metal may include at least one selected from an alkali metal complex and an alkaline earth metal complex. The alkali metal complex may include a metal ion selected from a lithium (Li) ion, a sodium (Na) ion, a potassium (K) ion, a rubidium (Rb) ion, and a cesium (Cs) ion, and the alkaline earth metal complex may include a metal ion selected from a beryllium (Be) ion, a Mg ion, a Ca ion, a strontium (Sr) ion, and a barium (Ba) ion. Each ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth metal complex may independently be selected from a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyl oxazole, a hydroxyphenyl thiazole, a hydroxydiphenylan oxadiazole, a hydroxydiphenylthiadiazol, a hydroxyphenyl pyridine, a hydroxyphenyl benzimidazole, a hydroxyphenyl benzothiazole, a bipyridine, a phenanthroline, or a cyclopentadiene; however, exemplary embodiments of the present invention are not limited thereto.

For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) and/or ET-D2:

The electron transport region 157 may include an electron injection layer 157′ that facilitates injection of electrons from the second electrode 190. The electron injection layer 157′ may be in direct contact with the second electrode 190.

The electron injection layer 157′ may have a single-layered structure including a single material, a single-layered structure including a plurality of different materials, or a multi-layered structure having a plurality of layers, each including a different material.

The electron injection layer 157′ may include the first component including at least one halide of an alkali metal (Group I), the second component including at least one organometallic compound, and the third component including at least one of a lanthanide metal and an alkaline earth metal (Group II).

The second electrode 190 may be disposed on the organic layer 150. The second electrode 190 may be a cathode, which may be an electron injection electrode. A material included in the second electrode 190 may be selected from a metal, an alloy, an electrically conductive compound, or a mixture thereof, which may have a relatively low work function.

The second electrode 190 may include at least one selected from Mg, Al, Al—Li, Ca, Mg—In, Mg—Ag, ITO, or IZO; however, exemplary embodiments of the present invention are not limited thereto. The second electrode 190 may be a semi-transmissive electrode or a transmissive electrode.

The second electrode 190 may have a single-layered structure or a multi-layered structure including two or more layers.

Referring to FIG. 2, an organic light-emitting device 20 may include a first capping layer 210, the first electrode 110, the organic layer 150, and the second electrode 190, which may be sequentially stacked in this stated order.

Referring to FIG. 3, an organic light-emitting device 30 may include the first electrode 110, the organic layer 150, the second electrode 190, and a second capping layer 220, which may be sequentially stacked in this stated order.

Referring to FIG. 4, an organic light-emitting device 40 may include the first capping layer 210, the first electrode 110, the organic layer 150, the second electrode 190, and the second capping layer 220, which may be sequentially stacked in this stated order.

Regarding FIGS. 2 to 4, the first electrode 110, the organic layer 150, and the second electrode 190 may each be substantially the same as the first electrode 110, the organic layer 150, and the second electrode 190 described with reference to FIG. 1.

In the organic layer 150 of each of the organic light-emitting devices 20 and 40, light generated in the emission layer 155 may pass through the first electrode 110, which may be a semi-transmissive electrode or a transmissive electrode, and the first capping layer 210 toward the outside. In the organic layer 150 of each of the organic light-emitting devices 30 and 40, light generated in the emission layer 155 may pass through the second electrode 190, which may be a semi-transmissive electrode or a transmissive electrode, and the second capping layer 220 toward the outside.

The first capping layer 210 and the second capping layer 220 may increase external luminescent efficiency according to the principle of constructive interference.

The first capping layer 210 and the second capping layer 220 may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or a composite capping layer including an organic material and an inorganic material.

At least one selected from the first capping layer 210 and the second capping layer 220 may include at least one material selected from a carbocyclic compound, a heterocyclic compound, an amine-based compound, a porphine derivative, a phthalocyanine derivative, a naphthalocyanine derivative, an alkaline metal complex, or an alkaline earth-based complex. The carbocyclic compound, the heterocyclic compound, and the amine-based compound may be substituted with a substituent including at least one element selected from O, N, S, Se, Si, F, Cl, Br, or I.

In an exemplary embodiment of the present invention, at least one selected from the first capping layer 210 and the second capping layer 220 may include an amine-based compound.

In an exemplary embodiment of the present invention, at least one selected from the first capping layer 210 and the second capping layer 220 may include the compound represented by Formula 201 or the compound represented by Formula 202.

In an exemplary embodiment of the present invention, at least one selected from the first capping layer 210 and the second capping layer 220 may include a compound selected from Compounds HT28 to HT33 and Compounds CP1 to CP5; however, exemplary embodiments of the present invention are not limited thereto.

An organic light-emitting device according to an exemplary embodiment of the present invention has been described above with reference to FIGS. 1 to 4. However, exemplary embodiments of the present invention are not limited thereto.

The layers included in the hole transport region, the emission layer, and the layers included in the electron transport region 157 may each be formed in a specific region using one or more suitable methods selected from vacuum deposition, spin coating, casting, a Langmuir-Blodgett (LB) method, ink-jet printing, laser-printing, and/or laser induced thermal imaging (LITI).

When the layers included in the hole transport region, the emission layer, and the layers included in the electron transport region 157 are each formed by vacuum deposition, for example, the vacuum deposition may be performed at a deposition temperature of about from about 100° C. to about 500° C., at a vacuum degree of from about 10⁻⁸ to about 10⁻³ torr, and at a deposition rate of from about 0.01 Å/sec to about 100 Å/sec, depending on the compound to be included in each layer, and the intended structure of each layer.

When the layers included in the hole transport region, the emission layer, and the layers included in the electron transport region 157 are each formed by spin coating, for example, the spin coating may be performed at a coating rate of from about 2,000 rpm to about 5,000 rpm, and at a temperature of from about 80° C. to 200° C., depending on the compound to be included in each layer, and the intended structure of each layer.

The term “C₁-C₆₀ alkyl group,” as used herein, may refer to a linear or branched aliphatic saturated hydrocarbon group having 1 to 60 carbon atoms, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a ter-butyl group, a pentyl group, an iso-amyl group, and a hexyl group. The term “C₁-C₆₀ alkylene group,” as used herein, may refer to a divalent group having the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group,” as used herein, may refer to a hydrocarbon group having at least one carbon-carbon double bond at one or more positions along the hydrocarbon chain of the C₂-C₆₀ alkyl group (e.g., in the middle and/or at either terminus of the C₂-C₆₀ alkyl group), and non-limiting examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group,” as used herein, may refer to a divalent group having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group,” as used herein, may refer to a hydrocarbon group having at least one carbon-carbon triple bond at one or more positions along the hydrocarbon chain of the C₂-C₆₀ alkyl group (e.g., in the middle and/or at either terminus of the C₂-C₆₀ alkyl group), and non-limiting examples thereof include an ethynyl group and a propynyl group. The term “C₂-C₆₀ alkynylene group,” as used herein, may refer to a divalent group having the same structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group,” as used herein, may refer to a monovalent group represented by -OA₁₀₁ (e.g., in which A₁₀₁ is the C₁-C₆₀ alkyl group), and non-limiting examples thereof include a methoxy group, an ethoxy group, and an isopropoxy group.

The term “C₃-C₁₀ cycloalkyl group,” as used herein, may refer to a monovalent saturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term “C₃-C₁₀ cycloalkylene group,” as used herein may refer to a divalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group,” as used herein, may refer to a monovalent saturated monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, and non-limiting examples thereof include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group,” as used herein, may refer to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group,” as used herein, may refer to a monovalent monocyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof, and does not have aromaticity. Non-limiting examples of the C₃-C₁₀ cycloalkenyl group include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group.” as used herein, may refer to a divalent group having the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group,” as used herein, may refer to a monovalent monocyclic group that has at least one heteroatom selected from N, O, Si, P, or S as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Non-limiting examples of the C₁-C₁₀ heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylene group,” as used herein, may refer to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group,” as used herein, may refer to a monovalent group having an aromatic system having 6 to 60 carbon atoms, and the term “C₆-C₆₀ arylene group,” as used herein, may refer to a divalent group having an aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each independently include two or more rings, the respective rings may be fused to each other.

The term “C₁-C₆₀ heteroaryl group,” as used herein, may refer to a monovalent group having a carbocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom and 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group,” as used herein, may refer to a divalent group having a carbocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, and 1 to 60 carbon atoms. Non-limiting examples of the C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each independently include two or more rings, the respective rings may be fused to each other.

The term “C₆-C₆₀ aryloxy group,” as used herein, may refer to a monovalent group represented by -OA₁₀₂ (e.g., in which A₁₀₂ is the C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthio group,” as used herein, may refer to a monovalent group represented by -SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group,” as used herein, may refer to a monovalent group that has two or more rings fused each other, only carbon atoms as ring-forming atoms (e.g., 8 to 60 carbon atoms), and non-aromaticity in the entire molecular structure. A non-limiting example of the monovalent non-aromatic condensed polycyclic group is a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group,” as used herein, may refer to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group,” as used herein, may refer to a monovalent group that has two or more rings fused to each other, has at least one heteroatom selected from N, O, Si, P, or S, other than carbon atoms (e.g., 1 to 60 carbon atoms), as ring-forming atoms, and has non-aromaticity in the entire molecular structure. A non-limiting example of the monovalent non-aromatic condensed heteropolycyclic group includes a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group,” as used herein, may refer to a divalent group having the same structure as the monovalent non-aromatic hetero-condensed polycyclic group.

The term “C₅-C₆₀ carbocyclic group,” as used herein, may refer to a monocyclic or polycyclic group having only carbon atoms as ring-forming atoms (e.g., 5 to 60 carbon atoms). The C₅-C₆₀ cyclic group may be a carbocyclic group or a non-aromatic carbocyclic group. The C₅-C₆₀ carbocyclic group may be a benzene group, a monovalent group such as a phenyl group, or a divalent group such as a phenylene group. In an exemplary embodiment of the present invention, depending on the number of substituents connected to the C₅-C₆₀ carbocyclic group, the C₅-C₆₀ carbocyclic group may be a trivalent quadrant group.

The term “C₁-C₆₀ heterocyclic group,” as used herein, may refer to a group having the same structure as the C₅-C₆₀ carbocyclic group, but including at least one heteroatom selected from N, O, Si, P, or S, other than carbon atoms (e.g., 1 to 60 carbon atoms), as ring-forming atoms.

At least one substituent selected from the substituted C₅-C₆₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, or the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), or —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, −Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), or —P(═O)(Q₂₁)(Q₂₂); or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂).

Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂ ^(-C) ₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, or a terphenyl group.

The expression “Ph” used herein may refer to a phenyl group, the expression “Me” used herein may refer to a methyl group, the expression “Et” used herein may refer to an ethyl group, the expression “ter-Bu” or “Bu^(t)” used herein may refer to a tert-butyl group, and the expression “OMe” used herein may refer to a methoxy group.

The term “biphenyl group,” as used herein, may refer to “a phenyl group substituted with a phenyl group”. As an example, a biphenyl group is a substituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The term “terphenyl group,” as used herein, may refer to “a phenyl group substituted with a biphenyl group”. As an example, a terphenyl group is a substituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The symbols * and *′ used herein, unless defined otherwise, refer to a binding site to a neighboring atom in a corresponding formula.

Hereinafter, a compound and an organic light-emitting device according an exemplary embodiment of the present invention will be described in more detail with reference to Synthesis Examples and Examples. The expression “B was used instead of A” used in describing Synthesis Examples may refer to an identical number of molar equivalents of A being used in place of molar equivalents of B.

EXAMPLES Example 1

As a substrate and an anode, an ITO glass substrate on which an ITO layer having at thickness of 15 Ω/cm² (about 1,200 Å) was formed was sonicated by using isopropyl alcohol and pure water for about 5 minutes each, and cleaned by exposure to ultraviolet rays for about 30 minutes, and then ozone, and the resulting ITO glass substrate was mounted on a vacuum deposition apparatus.

2-TNATA was vacuum deposited on the ITO glass substrate to form a hole injection layer having a thickness of about 600 Å. Then, NPB was vacuum deposited on the hole injection layer to form a hole transport layer having a thickness of about 300 Å.

98 weight % of CBP (as a host) and 2 weight % of PtOEP (as a dopant) were deposited on the hole transport layer to form an emission layer having a thickness of about 300 Å.

Alq₃ was deposited on the emission layer to form an electron transport layer having a thickness of about 300 Å. Liq (as a second component) was deposited on the electron transport layer to a thickness of 186 Å, and RbI (as a first component) and Yb (as a third component) were co-deposited on the Liq-containing layer at a volume ratio of 1:1 to a thickness of about 13 Å to form an electron injection layer and complete the formation of an electron transport region.

Ag and Mg were vacuum deposited on the electron transport region at a volume ratio of 5:1 to form a cathode having a thickness of about 100 Å, thus forming an organic light-emitting device:

Example 2

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Nal (as a first component) and Yb (as a third component) were co-deposited on the Liq-containing layer at a volume ratio of 1:1 to a thickness of about 13 Å, thus forming an electron injection layer.

Example 3

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Nal (as a first component) was deposited on the Liq-containing layer to a thickness of about 10 Å, and then, Yb (as a third component) was subsequently formed on the Nal-containing layer to a thickness of about 10 Å, thus forming an electron injection layer.

Comparative Example 1

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Yb alone was formed to a thickness of about 13 Å to form an electron injection layer.

Evaluation Example 1

Driving voltage, current density, and efficiency of each of the organic light-emitting devices of Examples 1 to 3 and Comparative Example 1 were each measured by using a Keithley SMU 236 and a PR650 luminance meter, and results thereof are shown in Table 1.

TABLE 1 Driving Current voltage density Efficiency Electron injection layer (V) (mA/cm²) (cd/A) Example 1 Liq/(RbI:Yb) 3.4 10.33 135.8 Example 2 Liq/(NaI:Yb) 3.9 8.8 152.6 Example 3 Liq/NaI/Yb 4.1 9.5 141.9 Comparative Yb 4.4 14.24 89.6 Example 1

Referring to Table 1, each of the organic light-emitting devices of Examples 1 to 3 had increased driving voltage, current density, and efficiency, compared to those of the organic light-emitting device of Comparative Example 1.

An organic light-emitting device according to an exemplary embodiment of the present invention exhibits a relatively long lifespan and relatively high efficiency.

It should be understood that embodiments described herein should be considered in a descriptive sense and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.

While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention. 

What is claimed is:
 1. An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and an emission layer disposed between the first electrode and the second electrode; and an electron transport region between the second electrode and the emission layer, wherein the electron transport region comprises an electron injection layer comprising a first component comprising at least one halide of an alkali metal (Group I), a second component comprising at least one organometallic compound, and a third component comprising at least one of a lanthanide metal or an alkaline earth metal (Group II).
 2. The organic light-emitting device of claim 1, wherein the first component comprises one selected from LiF, LiCl, LiBr, LiI, NaF, NaCl, NaBr, Nal, KF, KCl, KBr, Kl, RbF, RbCl, RbBr, Rbl, CsF, CsCl, CsBr, CsI, or any combination thereof.
 3. The organic light-emitting device of claim 1, wherein the first component comprises one selected from LIE, KCl, KI, RbCl, Rbl, or any combination thereof.
 4. The organic light-emitting device of claim 1, wherein the second component comprises at least one metal complex, wherein the at least one metal complex comprises at least one metal selected from lithium (Li), aluminum (Al), titanium (Ti), zirconium (Zr) , hafnium (Hf), zinc (Zn), or copper (Cu).
 5. The organic light-emitting device of claim 4, wherein the at least one metal complex comprises at least one organic ligand represented by Formula 1 or 2:

wherein, in Formulae 1 and 2, Z₁ and Z₂ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂), Q₃1 to Q₃₃ are each independently selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, or a carbazolyl group, e4 is an integer selected from 1 to 4, e6 is an integer selected from 1 to 6, and * and *′ each independently indicate a binding site to a metal.
 6. The organic light-emitting device of claim 4, wherein the second component comprises at least one compound selected from Compounds El-1 to El-9:


7. The organic light-emitting device of claim 1, wherein the third component comprises at least one selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium(Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra), or any combination thereof.
 8. The organic light-emitting device of claim 1, wherein third component comprises at least one of Yb or Mg.
 9. The organic light-emitting device of claim 1, wherein a volume ratio of the first component:second component is 100-x:x (wherein x is greater than 0, but is less than 100), and wherein a volume ratio of the first component:third component is 100-y:y (wherein y is greater than 0, but less than 100).
 10. The organic light-emitting device of claim 1, wherein a thickness of the electron injection layer is in a range of from about 2 Å to about 1,000 Å.
 11. The organic light-emitting device of claim 1, wherein the electron injection layer is in direct contact with the second electrode.
 12. The organic light-emitting device of claim 1, wherein the electron injection layer comprises at least one selected from: a film comprising the second component and the third component both dispersed within a matrix comprising the first component; a film comprising the first component and the third component both dispersed within a matrix comprising the second component; and a film comprising the first component and the second component both dispersed within a matrix comprising the third component.
 13. The organic light-emitting device of claim 1, wherein the electron injection layer comprises a first layer and a second layer, wherein the first layer comprises two components selected from the first component, the second component, and the third component, and the second layer comprises one component or two components selected from the first component, the second component, and the third component.
 14. The organic light-emitting device of claim 13, wherein the first layer is a film comprising the second component dispersed within a matrix comprising the first component, and the second layer is a film comprising the third component; or the first layer is a film comprising the third component dispersed within a matrix comprising the first component, and the second layer is a film comprising the second component; or the first layer is a film comprising the third component dispersed within a matrix comprising the second component, and the second layer is a film comprising the first component.
 15. The organic light-emitting device of claim 13, wherein the first layer is a film comprising the second component dispersed within a matrix comprising the first component, and the second layer is a film comprising the third component dispersed within a matrix comprising the first component; or the first layer is a film comprising the second component dispersed within a matrix comprising the first component, and the second layer is a film comprising the third component dispersed within a matrix comprising the second component; or the first layer is a film comprising the third component dispersed within a matrix comprising the first component, and the second layer is a film comprising the second component dispersed within a matrix comprising the first component; or the first layer is a film comprising the third component dispersed within a matrix comprising the first component, and the second layer is a film comprising the third component dispersed within a matrix comprising the second component; or the first layer is a film comprising the third component dispersed within a matrix comprising the second component, and the second layer is a film comprising the second component dispersed within a matrix comprising the first component; or the first layer is a film comprising the third component dispersed within a matrix comprising the second component, and the second layer is a film comprising the third component dispersed within a matrix comprising the first component.
 16. The organic light-emitting device of claim 13, wherein the first layer is in direct contact with the second electrode, and the second layer is disposed between the first layer and the emission layer.
 17. The organic light-emitting device of claim 13, wherein the second layer is in direct contact with the second electrode, and the first layer is disposed between the second layer and the emission layer.
 18. The organic light-emitting device of claim 13, wherein the first layer is in direct contact with the second layer.
 19. The organic light-emitting device of claim 13, wherein a thickness of each of the first layer and the second layer is in a range of from about 1 Å to about 500 Å.
 20. The organic light-emitting device of claim 1, wherein the electron injection layer comprises a first layer, a second layer, and a third layer, and wherein the first layer comprises the first component, the second layer comprises the second component, and the third layer comprises the third component. 